Francis presides historic double canonization

-General view of the crowd gathered for the canonisation mass of Popes John XXIII and John Paul II on St Peter''s square at the Vatican

Pope Francis proclaimed his predecessors John XXIII and John Paul II saints in front of more than half a million pilgrims today, hailing both as courageous men who withstood the tragedies of the 20th century.

Cheers and applause rang out across St Peter's Square after the historic double papal canonisation as many in the crowd fixed their gaze on huge tapestries of the two popes on the facade of the basilica behind Francis.

"We declare and define Blessed John XXIII and John Paul II to be saints and we enrol them among the saints, decreeing that they are to be venerated as such by the whole Church," Francis said in his formal proclamation in Latin.

Relics of each man - a container of blood from John Paul II and skin from John XXIII - were placed near the altar.

"These were two men of courage ... and they bore witness before the Church and the world to God's goodness and mercy," Francis said in his address.

"They lived through the tragic events of that (20th) century, but they were not overwhelmed by them. For them, God was more powerful; faith was more powerful," he added.

The crowd stretched back along Via della Conciliazione, the broad, half-kilometre boulevard that starts at the Tiber River.

The Vatican said more than 500,000 people filled the basilica area while another 300,000 watched the event on large television screens throughout Rome.

The Mass was also attended by former Pope Benedict, who last year became the first pontiff in six centuries to step down.

His attendance gave the ceremony a somewhat surreal atmosphere created by the presence of reigning pope, a retired pope and two dead popes buried in the basilica. Francis went over to greet Benedict twice during the service.

The fact that the two being canonised are widely seen as representing contrasting faces of the Church has added to the significance of an event that Francis hopes will draw the world's 1.2 billion Catholics closer together after a string of sex abuse and financial scandals.